1. Field of the Invention
The present invention relates to a hybrid integrated circuit device comprising a circuit substrate having an insulating substrate on which a wiring pattern is formed, circuit components which are mounted on the circuit substrate and lead terminals which protrude from one side of the circuit substrate in a given interval.
2. Prior Art
A well-known conventional hybrid integrated circuit device comprises a circuit substrate having an insulating substrate made of ceramics, glasses or epoxy resins on which a wiring pattern is formed, circuit components which are placed on the circuit substrate and lead terminals which protrude from the circuit substrate in a given interval. Particularly, in a single inline type (SIL type) hybrid integrated circuit device, the lead terminals protrude from one side of the circuit substrate.
The hybrid integrated circuit device having the arrangement set forth above is mounted on a parent circuit substrate which constitutes another circuit device. The SIL type hybrid integrated circuit device is mounted on the parent circuit substrate with the lead terminals thereof facing the parent circuit substrate. That is, the parent circuit substrate are perforated to form through holes in conformity with the intervals of lead terminals of the circuit substrate wherein the lead terminals are inserted into the through holes of the parent circuit substrate and the lead terminals are soldered to solder lands which are formed around the through holes.
Before the lead terminals are inserted into the through holes of the parent circuit substrate and are soldered to the solder lands, fine lead terminals are engaged in the through holes. As a result, the SIL type hybrid integrated circuit device is liable to fall down so that it is unstable and the lead terminals are liable to be bent. In this state, if the lead terminals are soldered to the solder lands of the parent circuit substrate, the connection between the circuit substrate and the parent circuit substrate by way of the lead terminals are liable to be unstable.
In view of the background as set forth above, there is proposed a clamping device for standing the SIL type hybrid integrated circuit device on the parent circuit substrate by itself. Such a clamping device is disclosed in Japanese Utility Model Laid-Open Publication No. 1-146574 and is denoted at a numeral 21 as illustrated in FIG. 5. The clamping device 21 is formed by inwardly bending the tip ends of a plate-shaped member which is folded in a substantial U-shape and further bending the tip end edges in substantial L-shapes. A through hole b is formed on the flat surface of the clamping device 21 in conformity with intervals of lead terminals 3 of the hybrid integrated circuit device and the lead terminal 3 is inserted into the through hole b and thereafter a circuit substrate 1 is clamped by the clamping device 21 at both sides thereof. Successively, the lead terminal 3 is inserted into the through hole b of a parent circuit substrate a while the flat surface of the clamping device 21 is mounted on the upper surface of the parent circuit substrate a whereby the circuit substrate 1 is allowed to stand on the parent circuit substrate a by itself. At this state, the lead terminal 3 of the circuit substrate 1 is soldered to a solder land c which is formed around the through hole b of the parent circuit substrate a.
However, a the hybrid integrated circuit device using such a clamping device has the following problems. That is, the hybrid integrated circuit device having an insulating resin package on the surface of the circuit substrate 1 has no large concave and convex portion on the surface thereof. However, according to the hybrid integrated circuit board having no insulating resin package on the surface of the circuit substrate 1 has concave and convex portions owing to the circuit components 2, 2 . . . which are placed on the circuit substrate 1 as shown in FIG. 5. Accordingly, the circuit substrate 1 is unstably clamped by the tip end edges of the clamping device 21. Furthermore, the circuit components 2, 2 . . . which are placed on the circuit substrate are liable to be damaged by the pressure and friction when they are clamped by the tip end edges of the clamping device 21.
Furthermore, the hybrid integrated circuit device is usually accommodated in a sheath-shaped stick so that the circuit substrate 1 is arranged vertically and is fed to the step where the circuit substrate 1 is mounted on the parent substrate. In this case, if the clamping device 21 is used, there is a likelihood that the tip end of a neighboring circuit substrate 1 will be clamped between the tip end edges of the clamping device 21 and the circuit substrate 1, which makes the hybrid integrated circuit device difficult to be moved in the stick or to be taken out from the stick. Whereas, if the hybrid integrated circuit device alone is accommodated in the stick without using the clamping device 21, there occurs such a problem that the end edges of the neighboring circuit substrates 1 overlap each other whereby the stick is crammed with the hybrid integrated circuit devices and the hybrid integrated circuit device is difficult to take out from the stick.